I own a 98 Durango, and I am trying to improve the performance. I have replaced exhaust and stock air filter can any one recomend a performance chip I was thinking of buying the JET chip.

 

I have read mostly that the Jet chip gives an initial performace boost, but after several hundred miles, the PCM starts to compensate for the chip. It happens gradually, but after some time, you have lost any gain it once gave. The best recommendations are to get a programmer, a custom flash, or a performance PCM.

For programmers, Hypertech and Superchips seem to be the best on the market, plus you can program for both premium and mid grade octane gas. Performance PCM's are good, but require that you run premium octane. Mopar also says not to use the perf. pcm if you tow.
There are some laptop tuners that allow you to custom flash your own PCM, but I know very little about them. A performance shop could also custom flash it for you too.

 

http://www.rpmoutlet.com/frame.htm

These guys have the best deal that includes a programmer/chip, cold air intake, and throttle body spacer. You can choose from several brands depending on what you want. As for what works best, I would recommed a programmer versus a chip. You may spend more, but it's way more convenient and there are more custom options. I only have experienced the superchips programmer in a Chevy Z-71, but had great results.

 

I priced a Mopar Performance PCM not too long ago; it was only $360.

When oil hits $35 a barrel like Steve Forbes thinks it will I may do it.